1. Field of the Invention
The present invention relates to a metal matrix composite (MMC) and a ceramic molded body used for manufacturing the metal matrix composite.
2. Description of the Related Art
Conventionally, a metal matrix composite is known where a metal is packed into a void (hereinafter referred to as “cell”) within a ceramic molded body (for example, see paragraphs 0008 to 0013 and FIGS. 6 and 10 in Japanese Patent Laid-Open Publication Hei. 6-170514 (hereinafter referred to as patent document 1)). The ceramic molded body used for the metal matrix composite is one where many porous cells are formed therein by sintering ceramic powders consisting of corundum and the like. Because the metal matrix composite obtained by filling a metal into the cell of such the ceramic molded body is excellent in mechanical strength such as an anti-wear property and the like, it is preferably used for a fine grinder plate for a paper making machine, a turbine blade, and the like.
In this connection, because in such a metal matrix composite a thermal expansion coefficient of a metal is larger than that of a ceramic molded body, a largeness and orientation of a thermal expansion of the metal packed into the cell greatly influence on a total thermal expansion coefficient of the metal matrix composite. On the other hand, because in a ceramic molded body (for example, see the patent document 1) used for a conventional metal matrix composite the cell thereof is constituted of amorphous porosities, a metal packed into such a porosity thermally expands in a porosity's extending direction. In other words, an anisotropy occurs in a thermal expansion of the metal distributing within the metal matrix composite.
As a result, because in the conventional metal matrix composite (for example, see the patent document 1) the anisotropy thus occurs in the thermal expansion of the metal, it becomes difficult to reduce the total thermal expansion coefficient of the metal matrix composite.
Accordingly, in spite of having an excellent mechanical strength, such the conventional metal matrix composite cannot be used as a member accompanying a large thermal change and requesting a dimensional stability.
Consequently, a metal matrix composite of which thermal expansion coefficient is reduced and a ceramic molded body used therefor are strongly requested.